Context
Coral reefs are highly valuable ecosystems that support biodiversity, coastal protection, and millions of people worldwide. However, they are rapidly declining due to climate-driven stressors such as warming, acidification, and deoxygenation. These factors disrupt coral physiology and lead to bleaching and mortality.
A major knowledge gap remains at the microscale, where corals exchange gases and nutrients with surrounding seawater. This exchange is controlled by the diffusive boundary layer (DBL)—a thin layer of water above the coral surface. Recent discoveries showed that corals actively modify this layer using epidermal cilia, which generate vortices that enhance transport. Until now, no tools existed to visualise these processes in 3D or link them to coral stress responses.
Overall Objectives
This MSCA project was designed to fill this gap by developing new optical imaging tools to understand how corals regulate their microenvironment under climate stress. The main objectives were:
- Produce the first 3D maps of oxygen and flow around corals using sensPIV.
- Develop pH-PIV, a new method to image pH and flow simultaneously.
- Determine how ciliary vortices influence coral resilience under warming, hypoxia, and acidification.
- Link external microenvironment patterns with internal tissue structure using OCT.
These goals integrate marine biology, biophysics, and advanced chemical imaging.
Scientific Impact
The project provides new mechanistic insights into how corals cope with climate stress at the microscale. The imaging tools developed allow researchers to study flow–structure–function interactions that were previously impossible to observe. These methods can also be used in other marine organisms and in biomedical systems where microscale fluid transport is important.
Societal and Environmental Impact
By identifying traits and species that better regulate their microenvironment, the project supports:
- improved reef restoration,
- better conservation planning,
- selection of stress-tolerant coral species,
- and evidence-based climate adaptation strategies aligned with EU policy goals, including the EU Biodiversity Strategy 2030 and the European Green Deal.
Given the high cost of restoration, even small increases in coral survival can create significant ecological and economic benefits.
